Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
During operation of a wind turbine, various components of the wind turbine are subjected to various loads. In particular, the shaft coupling the rotor blades and the generator may be subjected to various loads, such as axial and bending loads. Deflection of the shaft due to these loads may thus frequently occur during operation of the wind turbine.
In many cases, the deflection of the shaft may be measured and utilized to adjust other variables in the wind turbine, such as the pitch axis of the rotor blades. However, currently known systems and methods for measuring shaft deflection may not be accurate, any may thus provide inaccurate data for adjusting the other variables in the wind turbines. For example, currently known systems and methods may measure the deflection of one component of the shaft, such as the hub flange of the shaft. The sensors utilized to measure this deflection may be mounted to a base, such as to the pillow block assembly that is housing the shaft and support bearing for the shaft. However, during operation of the wind turbine, the base may also be subjected to various loads and deflections, along with the deflection of shaft. The sensors mounted to the base may thus receive inaccurate shaft deflection data due to the deflection of the base.
Thus, an improved system and method for measuring the deflection of a shaft in a wind turbine is desired. For example, a system and method that provide more accurate shaft deflection measurements would be advantageous. In particular, a system and method that reduce or eliminate extraneous deflection data due to the deflection of other components of the wind turbine would be desired.